Metal Segregation in Bimetallic CoPd Carbide Carbonyl Clusters: Synthesis, Structure, Reactivity and Electrochemistry of [H6−nCo20Pd16C4(CO)48]n− (n=3–6). Issue 12 (2nd October 2013)

• Record Type: Journal Article
• Authors: Ciabatti, Iacopo; Fabrizi de Biani, Fabrizia; Femoni, Cristina; Iapalucci, Maria Carmela; Longoni, Giuliano; Zacchini, Stefano
• Is Part Of: ChemPlusChem. Volume 78:Issue 12(2013:Dec.)
• Page Start: 1456
• Page End: 1465
• Publication Date: 2013-10-02
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1002/cplu.201300268
• Languages: English
• ISSNs: 2192-6506

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Nanometric CoPd bimetallic [H<sub>6−<italic>n</italic></sub>Co<sub>20</sub>Pd<sub>16</sub>C<sub>4</sub>(CO)<sub>48</sub>]<sup><italic>n</italic>−</sup> (<italic>n</italic>=3–6) tetracarbide carbonyl clusters have been prepared by redox condensation of [Co<sub>6</sub>C(CO)<sub>15</sub>]<sup>2−</sup> with [PdCl<sub>2</sub>(Et<sub>2</sub>S)<sub>2</sub>]. The crystal structures of both the dihydride tetra‐anion and monohydride penta‐anion have been determined as their [NEt<sub>4</sub>]<sub>4</sub>[H<sub>2</sub>Co<sub>20</sub>Pd<sub>16</sub>C<sub>4</sub>(CO)<sub>48</sub>]<bold>⋅</bold>4 CH<sub>3</sub>COCH<sub>3</sub> and [NMe<sub>3</sub>(CH<sub>2</sub>Ph)][NMe<sub>4</sub>]<sub>4</sub>[HCo<sub>20</sub>Pd<sub>16</sub>C<sub>4</sub>(CO)<sub>48</sub>]<bold>⋅</bold>5 CH<sub>3</sub>COCH<sub>3</sub> salts, respectively. The two species are isostructural and their structures display a perfect segregation of the two metals. They are composed of a cubic close‐packed (ccp) Pd<sub>16</sub> core stabilised on its surface by four {Co<sub>5</sub>C(CO)<sub>12</sub>} organometallic fragments. Their polyhydride nature has been corroborated by the study of their reactions with acids and bases, and confirmed by electrochemical studies. In addition, the reactions of [H<sub>2</sub>Co<sub>20</sub>Pd<sub>16</sub>C<sub>4</sub>(CO)<sub>48</sub>]<sup>4−</sup> with Na/naphthalene and PPh<sub>3</sub>/CO allowed the isolation of other lower nuclearity homoleptic and heteroleptic clusters, that is, [H<sub>6−<italic>n</italic></sub>Co<sub>16</sub>Pd<sub>2</sub>C<sub>3</sub>(CO)<sub>28</sub>]<sup><italic>n</italic>−</sup> (<italic>n</italic>=5, 6), [Co<sub>4</sub>Pd<sub>2</sub>C(CO)<sub>11</sub>(PPh<sub>3</sub>)<sub>2</sub>], [Co<sub>2</sub>Pd<sub>5</sub>C(CO)<sub>8</sub>(PPh<sub>3</sub>)<sub>5</sub>], and [Co<sub>4</sub>Pd<sub>4</sub>C<sub>2</sub>(PPh<sub>3</sub>)<sub>4</sub>(CO)<sub>10</sub>Cl]<sup>−</sup>. [H<sub>6−<italic>n</italic></sub>Co<sub>16</sub>Pd<sub>2</sub>C<sub>3</sub>(CO)<sub>28</sub>]<sup><italic>n</italic>−</sup> (<italic>n</italic>=5, 6) represent the first homoleptic metal–carbonyl clusters containing three interstitial carbide atoms.</p> </abstract>